Jupiter's moon Io is arguably one of the most volcanically active bodies in the Solar System. The reason, according to NASA's page Scientists to Io: Your Volcanoes Are in the Wrong Place is believed ...

According to the NASA JPL web-report, Gravity Gradients Frame Oceanus Procellarum, a rift-like ring structure surrounding the Moon's Oceanus Procellarum has been detected as a gravity anomaly by the ...